(Solved) - Desktop themes down on Windows 7

I have a 6 month old samsung laptop, at the moments the personalisation themes is unable to select any 'aero' themes (they are greyed out), it is stuck in classic windows look. It was working fine yesterday. It has done it before and mysteriously fixed itself, but I don't understand why. I didn't install or change anything before it happened either time.

Update: I shut down laptop and now I've turned it back on aero themes are working fine and are selectable whereas before they weren't. If anyine has any ideas why it keeps breaking then fixing I'd be very grateful.

Hi Lighthouse, now aero themes are working I checked themes in services and they are set as you say, annoying I can't check how they were set when it wasn't working. Thanks anyway